Batzal Ghost shader for MR is now FREEWARE!

Batzal Ghost is Mental Ray shader for creating layer transparency effect.
It allows you to fade out whole objects or whole particle effects into the background in only one render pass.
A similar effect can only faked by setting up another render pass which will involve extra rendering time, setting up masks and composition.
Even then, reflections and shadows behind your objects will not be rendered.
Batzal Ghost takes care of this for you.